From owner-freebsd-bugs@FreeBSD.ORG Thu Nov 18 02:00:31 2010 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A6A7A1065670 for ; Thu, 18 Nov 2010 02:00:31 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 688968FC0C for ; Thu, 18 Nov 2010 02:00:31 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id oAI20Vva074610 for ; Thu, 18 Nov 2010 02:00:31 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id oAI20Vpw074584; Thu, 18 Nov 2010 02:00:31 GMT (envelope-from gnats) Resent-Date: Thu, 18 Nov 2010 02:00:31 GMT Resent-Message-Id: <201011180200.oAI20Vpw074584@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Mateusz Guzik Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DF74C1065674 for ; Thu, 18 Nov 2010 01:56:50 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [IPv6:2001:4f8:fff6::21]) by mx1.freebsd.org (Postfix) with ESMTP id CD6B18FC14 for ; Thu, 18 Nov 2010 01:56:50 +0000 (UTC) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.14.3/8.14.3) with ESMTP id oAI1uo8L040150 for ; Thu, 18 Nov 2010 01:56:50 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.14.3/8.14.3/Submit) id oAI1uoeM040149; Thu, 18 Nov 2010 01:56:50 GMT (envelope-from nobody) Message-Id: <201011180156.oAI1uoeM040149@www.freebsd.org> Date: Thu, 18 Nov 2010 01:56:50 GMT From: Mateusz Guzik To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: bin/152345: truss writes one byte past the buffer if it is not null-terminated X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Nov 2010 02:00:31 -0000 >Number: 152345 >Category: bin >Synopsis: truss writes one byte past the buffer if it is not null-terminated >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu Nov 18 02:00:31 UTC 2010 >Closed-Date: >Last-Modified: >Originator: Mateusz Guzik >Release: 9.0-CURRENT >Organization: >Environment: FreeBSD lap 9.0-CURRENT FreeBSD 9.0-CURRENT #11 r213950+82afb7e: Sun Oct 17 16:57:50 CEST 2010 f@aa:/usr/obj/srv/repos/freebsd/sys/LAP amd64 >Description: When copying buffers filled by syscalls, truss does the following (syscalls.c: get_string()) buf = malloc(totalsize); Later, if buf is not null-terminated truss writes past the buffer: buf[totalsize] = '\0'; And if buf[totalsize - 1] is not 0, one-byte garbage is printed along with expected data. >How-To-Repeat: Download and compile http://student.agh.edu.pl/~mjguzik/truss_garbage.c . It will try to readlink(2) symlink 'foo' to a buffer filled with 0xFF. $ ln -s bar foo $ truss ./a.out 2>&1 | grep readlink readlink("foo","bar˙",1025) = 3 (0x3) >Fix: See http://student.agh.edu.pl/~mjguzik/truss_garbage.patch >Release-Note: >Audit-Trail: >Unformatted: